Histological analyses of mouse models of RP involving an alternative mutation in Pde6b (rd1), and mutations in other photoreceptor genes (rd16 and RPGRIP−/−), demonstrated similar evidence of microglial phagocytosis of TUNEL–photoreceptors (Fig4A–C), as did histopathological specimens of human RP, including autosomal recessive, autosomal dominant, and X-linked forms (Fig4D–G), indicating microglial phagocytosis of stressed rods as a generalized mechanism underlying RP. Here, PDE6B is linked to retinitis pigmentosa 1.